风积细粒防渗土料掺砾比研究

发布时间：2018-03-16 12:53

本文选题：风积　切入点：粉粒　出处：《地下空间与工程学报》2017年06期 　论文类型：期刊论文

【摘要】：某水电站设计最大坝高150 m,拟采用碎石土心墙堆石坝,但特殊的地质、地理、气候等因素导致工程区及外围缺乏优质防渗土料。通过大量的试验研究,笔者认为风积粉土(Qeol4)可作为天然防渗土料,其物理性质、力学特性、渗透系数等质量指标基本满足要求。但作为高坝心墙防渗体土料,力学强度相对较低,必须进行工程特性改良,即掺入人工碎砾石料。研究表明:在不同的掺砾比试验条件下,粘粒、粉粒含量随掺砾料的增加而减少,且P_5(掺砾料5 mm颗粒含量)与最大干密度ρ_(dmax)、最优含水率ω_(0p)具有相关性;当掺砾率为40%时,压缩特性和力学强度大幅度提高的同时,渗透系数最小,因此确定其为最优掺砾率。研究成果为该坝的可行性提供了重要技术支撑,具有重大的工程意义。
[Abstract]:The maximum dam height of a certain hydropower station is 150m, and the rockfill dam with gravel core wall is to be adopted, but the special geological, geographical and climatic factors lead to the lack of high quality impermeable soil material in the engineering area and its periphery. The author thinks that the eolian silt (Qeol4) can be used as natural impervious soil material, and its physical properties, mechanical properties, permeability coefficient and other quality indexes can basically meet the requirements, but as a high dam core wall impervious soil material, the mechanical strength is relatively low. It is necessary to improve the engineering characteristics, that is, to add artificial gravel. The results show that the content of clay and powder decreases with the increase of gravel admixture under different test conditions. Moreover, there is a correlation between P5 (particle content of gravel 5 mm) and the maximum dry density 蟻 / D _ (max), the optimum moisture content 蠅 _ (0) p), and when the gravel ratio is 40, the permeability coefficient is the smallest when the compression characteristics and mechanical strength are greatly increased. The research results provide important technical support for the feasibility of the dam and have great engineering significance.
【作者单位】：中国电建集团成都勘测设计研究院有限公司;成都理工大学地质灾害防治与地质环境保护国家重点实验室;
【分类号】：TV41

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